Fluid actuated device



Afiril '3'," 1945.

F. MARTINDELL.

FLUID ACTUATED DEVI CE Original Filed Nov. 7, 1942 2 Sheets-Sheet 2 //V VE/V TOE F MAR TINDEL L Patented Apr. 3, 1945 2,373,042 FLUID ACTUATED DEVICE Frank Martindell, Wes Western Electric New York, N. Y., a co Original application Nove tern Springs,

Company, Incorporated, rporation oi' mber 7, Divided and this application May 8,

1943, Serial No. 486,228

6 Claims. (Cl. 177-311) This invention relates to fluid actuated devices and particularly to such devices responsive to conditions of fluid flow co-pending application, Serial No. 464,900, flled November '7, 1942,

The invention is particularly applicable, for example, to arc welding operations in a hydrogen atmosphere under a welding hood. 'In such welding operations, the flow hood, at times, may stop, due to either failure of the source of supply or clogging in the conduit connecting the source to the hood. In such cases, it is desirable that a signal be automatically given to the operator.

An object of the invention is to provide a practicable and reliable fluid actuated device responsive to conditions of fluid flow.

In accordance with one embodiment of the invention as applied to arc welding operations under a reciprocatory hood in a hydrogen atmosphere, there is provided a device operating from the pressure differential, efl'ected by conditions of flow between a hydrogen supply conduit connected thereto, which includes a capillary tube or other suitable member having a restricted orifice and a connected restricted outlet conduit communicating with the welding hood and means actuated by the device, which is responsive to a normal flow of the hydrogen as well as a stoppage of flow thereof either at the inlet or restricted outlet sides of the device, due to either failure of the supply source or clogging of the outlet, or within the'capillary tube, to give a signal to the operator.

Other objects and advantages of this invention will more clearly appear from the following detailed description, taken in connection with the accompanying drawings, in which Fig. 1 is a front elevation of a hydrogen flow actuated device, embodying the features of the invention shown, connected to a hydrogen supply conduit for supplying a hood of an arc welding apparatus with hydrogen;

Fig, 2 is a plan section, partly in elevation, taken on the line 2-2 of Fig. 1;

Fig. 3 is a diagrammatic view of portions or the combined hydrogen flow indicator and electrlc circuit controlling device for indicating hydrogen flow conditions from the supply source through the device and into the hood and for preventing completion or the welding circuit until the hydrogen has flowed into the hood for a predetermined time, the circuit being shown operated in response to anormal hydrogen flow condition; and

of hydrogen into the and is a division of my 1 under a very slight pressure.

New York 1942, Serial No.

Figs. 4 and 5 are fragmentary views of Fig. 3 showing the device and circuit operated in re sponse to a stoppage of hydrogen flow to the hood and a clogging in the capillary tube, respec-' tively.

Referring to the drawings in detail and particularly to Figs. 1 and 2, a fluid actuated device responsive to conditions of fluid flow, indicated, in general, at l0 (Fig. 1) is provided for use in connection with arc welding performed under a hydrogen atmosphere, or other inert gaseous mediums, in a bell or hood indicated at H (Fig. 3). The device l0 comprises a base l2, which is attached to a standard or frame (not shown) and fixed to the base are two spaced and aligned cored members It and I5, to which are connected hydrogen inlet and outlet conduits l1 and I 8, respectively, the member l4 providing an inlet chamber and the member l5 an outlet chamber. The inlet conduit I! is connected to a suitable constant supply source, shown schematically at [3 (Fig. 2), for hydrogen under, for example, approximately four pounds pressure, a, pressure regulating valve being indicated at IS. The outlet conduit l8 is of that it provides a restricted outlet from the device to produce a back pressure in the outlet chamber, the hydrogen passing through the device into the hood H, where it flows thereinto The cored members H and I5 are in communication with each other by means of an interconnecting capillary tube 19 or other suitable member having a restricted orifice. Rigidly supported on and in communication with the interior of the cored member I4 is a bellows 20, which is responsive to four pounds pressure per square inch, and similarly supported and in communication with the interior of the cored member I5 is a bellows 2|, which is responsive to one pound per square inch of pressure, the two bellows being in axial alignment. The opposed free inner sealed ends of the bellows 20 and 2| each carry an adjustable headed screw 24, which constantly engage opposite sides of a vertical arm 25 pivoted at its lower end at 26 to the base l2. Adjustably mounted in the upper end of the pivotal arm 28 are adjustable switch actuating screws 21 and 20.

Attached to the base l2 above the capillary tube It and bellows 20 and 2| is a bracket 29, upon opposite sides of which are secured normally open and closed micro-switches 3| and 32 of a standard commercial type having operating plungers 33 and 34, respectively, the switch actuating screws 21 and 20 being aligned with the plungers.

such length or cross-section- -the pressure on the The arm 25 is maintained in a normal initial position when no hydrogen is flowing through the device through the action of a spring pressed plunger 35 constantly engaging the arm, the plunger being carried by an adjustable housing 35 carried on a bracket 31 fixed to the base it. Adiustably carried by the bracket 31, below the plunger 35, are two adjustable stop screws 39 and ill, one at each side of the pivotal arm 25. for limiting its movement in either direction about its pivot in the normal initial position of the arm 25, it engages the stop screw 39,

at which time the switches 3i and 32 are in their normal open and closed positions, respectively.

In the use of the fluid actuated device ill, above described, the compressed hydrogen flows into the device. through the inlet conduit ii and thence through the member or chamber 2, capillary tube l9, member or chamber [5 and restricted outlet conduit id to the interior of the welding hell or hood ll (Fig. 3). The inlet and outlet pressures in the chambers it and it and capillary tube it are also impressed upon the bellows 2d and 2!, respectively. The device ill operates on the pressure difierential between the inlet and purpose of providing a turntable outlet ends of the capillary tube lb and when the normal desired flow of hydrogen through the device and into the bell or hood ii is being maintamed, the arm 25, receiving motion from the pressure responsive bellows 2%, will move clockwise about its pivot 2% (Fig. 1) against the action of the spring-pressed plunger 35 and assumes such a position that the switch actuating screw 2?, carried by the arm 2%, will operate the normally open switch 3i through its operating plunger 33 to its closed position, as shown in Fig. 1 and in diagrammatic view Fig. 3, such position of the arm not affecting the normally closed switch 32. The operation of the combined indicating and safety control circuit (Figs. 3, 4 and 5), which includes the switches 3i and 32, will be described presently.

In the case of complete stoppage of the hydrogen fiow through the restricted outlet conduit id of the device ill, iollowing the capillary tube l9, due to clogging therein or a. failure of the supply source, the pressures in both of the bellows 2G and 22 will be equalized, thus permitting the arm 25 to move counterclockwise, through the action of the spring-pressed plunger 35, and assume such a position that it will engage the stop screw 39. In response to this latter movement of the arm 25, the switch ill is permitted to return to its normally open .position. If the device 58 should become clogged in the capillary tube to, bellows 28 will be so great that the arm 2% will be moved clockwise against the action of the spring-pressed plunger. 35 sufficiently not only to close the normally open switch 38 but to open the normally closed switch 32, which condition is illustrated diagrammatically in Fig. 5, this latter movement ofthe arm 25 being limited by its engagement with the stop screw til.

Referring to the diagrammatic views, Figs. 3, 4 and 5, and particularly to Fig. 3, wherein is illustrated the hood or bell H in which arc welding is performed in a hydrogen atmosphere, the hood H is provided with a window :36 ofsuitable transparent material an operator may insert and manually manipulate an electrode :38 having a. handle 49. Disposed below the electrode 638 in the hood H is an elecand has an opening 41 whereby 'f trode 5B, which is shown in the form. of a turn-= I semblages 52 to be are welded are suitably held. A depending shaft 53 attached to the electrode turntable bi is ioumalled in a supporting frame Eli of the welding apparatus. Attached to the closed upper end wall of the hood ii is a shaft 55, which is reciprocated by suitable means (not shown) for the purpose or elevating and lowering the hood ll. After each welding operation, the turntable electrode to is rotated, by suitable astuating means (not shown) connected to the shaft 53, to position another assemblage of worlr pieces 52 in position for welding. after the plurality of assemblages of work pieces 52 carried on the turntable electrode Eli are welded, the hood H is elevated sufficiently to permit the removal of the welded work pieces 52 and to reload the turntable. Thereafter, the hood ii is lowered and the welding operations are repeated. The electrode 5% and supporting a plinality of worls piece assem blages thereon is to perform the welding operation in. a hydrogen atmosphere in an economical and practical manner. in order to economize in the use of the hydrogen which is constantly flowing into the hood ll, it is desirable that the operations of raising and lowering the hood be held to a minimum since each time the table is raised, hydrogen is wasted and further each time the hood is raised and lowered, it is necessary that the hydrogen should flow thereinto for a predetermined time in order to fill it and remove the air therefrom in order that the welding operations may safely follow. To further this econcm in the us of the hydrogen, which is constantly flowing during normal operations into the hood M by means of the conduit is connected to the chamber id at the outlet end ofthe hydrogen flow actuated device iii, the following arrangement is provided. The hood H has attached to its inner wall, as indicated at 55, a conduit 59, which is telescopically entered in the bore oi the conduit Iii. The upper end of the conduit 59 is open, or it may be closed, and its wall apertured to permit the flow or hydrogen therefrom into the hood. Thus, in any position of the hood ii, the hydrogen will flow thereinto at a fixed plane adjacent its upper closed end.

The combined indicating and safety control circuit (Fig. 3) which includes the micro-switches 3i and 32, connected in series in the circuit, also includes a battery 5%, or other source of electric energy, an electric lamp 6 l or other signal device, and a retarded relay 62, which, upon energizetion, is slow to operate its armature to, which is shown as engaging a circuit closing contact 66, all suitably connected in the circuit. Also included in this circuit is a third normally open micro-switch 55, similar to the switch 35, having an operating plunger 55 lying in the path of a switch actuating member or carried by the reclprocatory hood H, the member or closing the switch .55 in the final period of movement of the hood to its lowered position. In Fig. 3, the combined indicating and control circuit have been completed by the closing of the normally open micro-switches 3i and 65, in the or hereinbefore demribed, it being asumed that a normal how of hydrogen is passing through the device id and the conduit 58 into the welding hood H. Thus, the lamp 6! is lighted, indicating the hydrogen flow is normal, and the armature 63 of the retarded relay 62 has been operated upon lapseof a predetermined period of time sufiicient to insure that the welding hood H is filled with hydrogen and void of air. As shown, the operated relay armature 63 has engaged the contact tion has been described hereinbefore as applied to an arc welding apparatus, wherein hydrogen is used, it is clear that it may have a more general application and other inert gaseous mediums may be used and that modifications can be made.

What is claimed is:

1. In a fluid actuated indicator device responsive to conditions of constant fluid flow between a fluid supply source and the point of use of the fluid, a pair of fluid pressure actuated bellows, a member having a constant restricted the opposite end of said tube and to its connected bellows, and an arm actuated by differential pressure on said bellows for indicating fluid flow conditions at said outlet conduit.

4. In a fluid flow indicator device, a source of constant fluid pressure to provide a fluid flow, a pivotal lever, means including a pair of opposed expansible bellows connected to said source each orifice communicating at opposite ends with said bellows, fluid inlet and restricted outlet conduits communicating with said bellows and member, an arm actuated by differential pressure on said bellows, and means responsive to predetermined movements of said arm for indicating fluid flow conditions at said outlet conduit.

In a fluid actuated indicator device responsive to conditions of constant fluid flow between a fluid supply source and the point of use of the fluid, a pair of fluid pressure actuated bellows, an inlet chamber connected to one of said bel- --lows, an outlet chamber connected to the other of said bellows, a capillary tube having a constant orifice connected at opposite ends with said inlet and outlet chambers, a fluid inlet conduit connected to said inlet chamber, a restricted outlet conduit connected to said outlet chamber, and

an arm operatively associated with both of said one end connected to one 01 said bellows and its 50 opposite end connected to the other of said bellows, a fluid inlet conduit communicating with one end 01' said tube and to its connected bellows, a restricted outlet conduit communicating with supported at one end and at their free opposite ends being operatively engaged with said lever for moving the same, a member having a constant restricted orifice communicating at opposite ends with said bellows at their supported ends, and

fluid inlet and restricted outlet conduits in communication with the opposite ends of said member, the movements of said lever being in response to variation of the pressure between said bellows and the resultant positions of the lever being effective to indicate fluid flow conditions at said outlet conduit.

5. In a fluid flow indicator device, a base, a lever pivoted thereon, a source of constant fluid pressure to provide a fluid flow, means including a pair of opposed diiierentially expansible bellows connected to said source each supported at one end on said base and at their free opposite ends operatively engaged with said lever for moving the same in response to differential and equalized pressure between said bellows, a member having a constant restricted orifice communicating at opposite ends with said bellows, fluid inlet and restricted outlet conduits connected to opposite ends of said member, and means responsive to predetermined movements of said lever for indicating fluid flow conditions at said outlet conduit. 6. The combination with an apparatus which includes a hood containing an inert gaseous medium, a source of constant gaseous medium pressure to provide a gaseous medium flow, of a gaseous medium flow indicator device communicating with the hood, said device comprising a pair of fluid pressure actuated bellows connected to said source, a capillary tube having a constant oriflce communicating at opposite ends with said bellows, fluid inlet and restricted outlet conduits communicating with said bellows and capillary tube, said restricted outlet conduit communicating with the interior of the hood, an arm actuated by diflerential pressure on said bellows, and means responsive to predetermined movements of said am for indicating gaseous medium flow conditions at the interior of the hood.

FRANK MARTINDELL. 

